Joint sealing device



L. c. WANGEZROW 3,521,528

JOINT SEALING DEVICE OriginalFiled March 25, 1966 July 21,1970

FIG. 4

IN-VENTOR LEROY C. WANGEROW BY T Togrggtv United States Patent Office3,521,528 Patented July 21, 1970 3,521,528 JOINT SEALING DEVICE Leroy C.Wangerow, Oak Lawn, Ill., assignor to W. R. Grace & Co., Cambridge,Mass., a corporation of Connecticut Continuation of application Ser. No.537,539, Mar. 25, 1966. This application Feb. 28, 1969, Ser. No. 806,003Int. Cl. E01c 11/00; F16j 9/00 US. CI. 9418 3 Claims ABSTRACT OF THEDISCLOSURE This is a continuation of application, Ser. No. 537,539 filedMar. 25, 1966, now abandoned.

This invention is concerned with sealing strips for joints in concretestructures.

The object of the invention is to provide a distortable, compressiblejoint strip which will maintain full wall contact with the opposingmargins of the concrete slabs despite changes in the width of the jointcaused by the expansion and contraction of the concrete with temperaturechange. i

As the specification proceeds, it will become apparent that the sealingstrips of this invention are suitable for sealing transverse andlongitudinal expansion and contraction joints in highways, airportrunways, building floors, ramps, sidewalks, etc., and are useful also inconstruction joints. Changes which render the sealing strip suitable forthese various uses are dimensional, and include principally theselection of the proper size of strip to fit the anticipated thermalmovement of the joint. Since the strips for all types of joints aresimilar, one type a sealing strip for the expansion joint betweenconcrete highway slabswill be set forth as the preferred example.

Because concrete does expand and contract to a limited degree, aconcrete highway must be provided with expansion joints to allow for thedimensional change.

A common method of forming an expansion joint between highway slabs isto place a joint fillera slab of compressible material, often about /1of an inch thick at the end of each specified slab length and transverseto the high-way. The joint filler extends vertically from at or slightlybelow the subgrade to approximately 1" below the road surface. The gapabove the joint filler must be sealed to prevent the entrance of waterand debris.

It has previously been the practice to seal the gap between the concreteslabs and above the joint filler with a plastic composition, usuallybituminous, to prevent the entrance into the joint of water and debris.More recently, hollow rubber sealing elements called preformed sealingstrips have been used and have proved to be desirable and long lasting.In particular, they are free from the cold-flow difficulties which areassociated with joints sealed with plastic compositions and, generallyspeaking, better resist the up-thrust caused by ice and frost in thesubgrade which pushes plastic seals above the highway surface. Preformedseals, preferably in continuous lengths which reach the full width ofthe slab, are forced into the gap either by hand or by machine.

In the development phase of this invention, numerous configurations ofhollow rubber joint seals were made and were subjected to compressionand expansion tests between concrete slabs in a compression-testingmachine. It was found that when the walls of the seal which wereintended to lie in contact with the transverse margins of the concreteslab were compressed towards each other, the central area foldeddownwards, and pulled the upper marginal portion of the seal with itaway from contact with the concrete.

In FIG. 4, views a, b, and 0 illustrate the distorted shapes which areassumed by the joint seals not made in accord with this invention. Viewa illustrates the shape assumed by a joint seal 19 having parallel planeside walls and an X-braced internal structure. The crumpled condition ischaracteristic. View b shows a seal 21 having the same external shape.Forced between slabs 20 it formed two small gutters between the seal andthe concrete slabs. It, too, has an X-shaped reinforcement in its bore.However, the X was in a different vertical position. View c shows theconfiguration assumed by a sealing strip 22 having parallel side walls,a centrally located vertical diaphragm, and a chevron-shaped butgenerally horizontal diaphragm located at the mid-point. The uppermargin of this design pulled inwardly and away from the concrete wallsand formed two small gutters.

Seals which pull away in a narrow line adjacent the concrete margin forma gutter which, with highway use, collects dirt and debris. Undertraffic conditions, the debris continually is pounded downwards andbetween the wall of the rubber seal and the concrete slab. Ultimatelythe expansion joint fills with uncompressible matter.

I have discovered that these distortions and their deleterious effectswill not occur if small projections extending beyond the normal sidewalls of the seal are formed at, or substantially at, the top margin ofthe seal. Instead, the projections or sealing tips press against theends of the slab and have the effect of forcing the entire side wall ofthe sealing strip into contact with the slab walls.

When in position between the concrete slabs, my improved sealing stripassumes the configuration shown in FIG. 2. As a result, a tight,effective seal is formed.

Referring to the drawing:

FIG. 1 is a vertical cross-section of the presently preferred form ofthe sealing strip;

FIG. 2 is a vertical cross-section showing the strip when wedged betweentwo opposing concrete highway slabs;

FIG. 3 is a vertical cross-section of an alternate form; and

FIG. 4 shows in dotted outline the various distorted shapes assumed by Xand chevron type sealing strips with no marginal bead when the stripsare under compression.

The sealing strip, 10, is a rubber or plastic tube extrusion, preferablyhaving vertical side walls, 11, a chevron shaped top wall, 12, a chevronshaped bottom wall, 13, a mid partition, 14, and a bracing diaphragm,15, also of chevron shape.

The sealing tips, 16, are formed as a continuous, preferably pyramidal,bead located at the junction of the top wall, 12, and each side wall,11, and extend outwardly from the walls, 11.

The seal, 10, may be formed of plastic, rubber or of any of the age andoil resistant so-called rubber polymers such as chlorobutadiene,butadiene-acrylonitrile, polyisoprene blends, or polyurethane,polybutene with isoprene or butadiene, ethylene-propylene, polyvinylchloride, etc. All of these materials give satisfactory performance.

The actual dimensions of the seal will be those as set by the highwayspecifications, but a dimension which gives satisfactory performance hasbeen found to meet a majority of highway specifications as follows:

Width between side walls when expanded Thickness of side walls andcentral web% Thickness of top Wall% Overall depth1" Dip of chevron inthe top wall Dip of chevron in the bottom wall Projection of tip beyondside wall- A It should be understood that the above dimensions areillustrative only; seals embodying the invention may also beconsiderably larger.

After the gap in the pavement has been formed by lifting the installingcap and finishing the margins, and the gap has been brushed out andcleaned, a continuous length of sealing strip of FIG. 1 is laid acrossthe highway and forced into the opening between the adjacent concreteslabs. Forcing the strip into the gap between the slabs may be done byhand by pressing the strip from above with any implement which is nowider than the gap. Care must be taken to prevent the strip fromtwisting as it is being forced downwards. Somewhat better and quickerresults are secured when a mechanical strip inserter is used, since thestrip is held from twisting by the nose of the machine, and a disc orwheel which fits between the concrete slabs, pressing down on the seal,forces it into position.

Such sealing strips possess all of the well-recognized advantages ofrubber preformed highway seals which, in contrast to an asphalt seal, donot have to be chiseled down to the road surface to remove the wintersupthrust. When necessary, they can be quickly removed, the joint areacleaned out, and the seal can be either reinserted or replaced withsimple tools. No hot tar pot is required, but seals, when improved withthe top marginal bead herein disclosed, will remain in service forconsiderably longer times than previously has been possible, since dodirt or debris is forced down between the sealing strip and the concreteto accumulate and force the strip out of position.

Although the sealing strip with vertical side Walls and generally ofchevron shape has been set forth as the preferred example, it has beenfound that other shapes, e.g., circular (see FIG. 3), make effectiveseals, provided that longitudinal sealing beads, 17, projecting beyondthe normal outside wall, 18, of the seal are formed at the intendedjunction of the top surface and the side walls.

The sealing tip, 16, may have any cross-section which concentrates themaximum side thrust of the sealing element against the concrete in anarrow band adjacent the top longitudinal margin of the element. Apyramid, which concentrates the maximum thrust along a line, performsideally, but other shapes, e.g., a single small rectangle, formsatisfactory seals, and greatly reduce the distortion of the sealingelement over that of a seal having an extensive wall contact.

It is claimed:

1. A preformed element adapted to form the flexible sealing member in anexpansion joint of a concrete structure comprising a rubber tube, theperiphery of which exhibits a chevron-shaped top and bottom wall and two7 parallel side walls joining said top and bottom walls, said side wallshaving upper marginal portions and smooth exterior surfaces, said tubehaving a vertically extending diaphragm connecting said top and bottomwalls, and said tube bearing means to prevent said upper marginalportions of said side walls from pulling away from the vertical face ofa concrete slab consisting of two continuous beads, one each of saidbeads being formed at the junction of each side wall with said top wall,said beads being substantially normal to and extending outwardly fromsaid side walls, whereby continuous contact of said element with saidvertical face is maintained and inward distortion of said side walls isprevented when said element is compressed between opposed slabs.

2. A preformed joint sealing element adapted to form the flexiblesealing member in an expansion joint of a concrete structure comprisinga rubber tube, the periphery of which exhibits chevron-shaped top andbottom walls and two parallel side walls joining said top and bottomwalls, said side walls having upper marginal portions and smoothexterior surfaces, said walls being interiorally reinforced by ahorizontal chevron-shaped diaphragm connecting said side walls and avertical diaphragm connecting said chevron-shaped top, said horizontalchevronshaped diaphragm and said chevron-shaped bottom wall at thecrests of said chevron, said tube bearing means to prevent said uppermarginal portions of said side walls from pulling away from the verticalface of a'concrete slab consisting of two continuous beads, one each ofsaid beads being formed at the junction of each side wall with said topwall, said beads extending substantially normal to and outwardly fromsaid side walls, whereby continuous contact of said element with saidvertical face is maintained and inward distortion of said side walls isprevented when said element is compressed between opposed slabs.

3. The element of claim 2 wherein said beads have a pyramidalconfiguration comprising a base and a conical portion extendingtherefrom, said base being adjacent said top wall.

References Cited UNITED STATES PATENTS OTHER REFERENCES Acme HighwayProducts Corp. (Trade Publication), Received July 17, 1963, 4 pages(note page 3), Class 94, sub 18.2.

SAMUEL ROTHBERG, Primary Examiner US. Cl. X.R. 277-207

